Planning for the Weather

[Shawn]

Hey - thanks Dave for the info. I haven't looked at the CDEC stuff for a long time; some really nice improvements to the map of all the (very) many remote stations make it much easier to navigate.

I looked at the WX data for Farewell Gap, as shown below. What do you imagine is the data for the Snow WC indicating when it goes from a positive reading at night to a negative reading by day and back to a positive value again?

Date / Time SNOW WC
10/19/2015 01:00 19.60
10/19/2015 02:00 19.46
10/19/2015 03:00 25.04
10/19/2015 04:00 15.47
10/19/2015 05:00 17.72
10/19/2015 06:00 -3.72
10/19/2015 07:00 -6.54
10/19/2015 08:00 -2.73
10/19/2015 09:00 -6.55
10/19/2015 10:00 0.70
10/19/2015 11:00 10.25
10/19/2015 12:00 11.62

[SSSdave]

I'd guess one issue with some sensors is mechanisms getting stuck from freezing water and riming. Remote sites also use solar cells and batteries that when temperatures drop low at night will have less output so might give odd readings.

[Shawn]

Ah, that must be it; thanks.

[maverick]

Need a refresher course on understanding/reading mountain weather, this is a good one:

http://pafc.arh.noaa.gov/classroom/prac ... untain.php

[longri]

Need a refresher course on understanding/reading mountain weather, this is a good one:

http://pafc.arh.noaa.gov/classroom/prac ... untain.php

When I click that link I get redirected to here:

http://www.weather.gov/afc/

Looks like NOAA took it down sometime in the last year.
It's on archive.org from 2016:

https://web.archive.org/web/20160203045 ... untain.php

At least most of it is. You might have to look back further in time for one or more of the chapters.
Maybe someone has archived it elsewhere on the web?

How good is it? I frequently get field forecasts wrong, sometimes very wrong.

[JosiahSpurr]

I primarily use these two methods when I go backpacking/camping. I find them reliable.

1. Weather.gov. Simply put in the nearest down name or zip code in the upper left where it says "Local forecast by "City, St" or ZIP code. Click the "Go" button and the page will refresh to that town. Here is where you can customize it to your exact location. See the Google Map on the right? Use your mouse to move the map to where you will actually be hiking. Then click on that spot. The page will refresh and you will get a customized weather forecast up to 10 days for that location. I tend to click on different elevations to get an idea of what to expect. I also check this the night before or morning of my trip to get the latest.

2. Amatuer Radio. [...]

Yes, I use number #1 all the time.

Yet, the snow accumulations always seem too low. For example, this is the prediction for "9 Miles WSW Lone Pine CA
36.54°N 118.22°W (Elev. 9501 ft)":

Tonight ... Total nighttime snow accumulation of less than a half inch possible.
Saturday ... New snow accumulation of less than a half inch possible.
Saturday Night ... New snow accumulation of less than a half inch possible.
Sunday ... New snow accumulation of around an inch possible.
Sunday Night ... New snow accumulation of less than a half inch possible.

if you add up all those "possibles," the total accumulation for this storm according to Weather.gov is.... three inches. It often talks in terms of "half an inch" and "an inch," but at that elevation, a lot more could fall.

So, I realized that it's important to get an overview of the weather system that's causing the prediction. They put the beginning of the overview at the top of the NWS home page. Then, you have to click "More>" to read the whole thing. Right now, it says:

"..... as a developing strong storm over the Rockies will produce heavy snow. Heavy snow will develop across the Northern Rockies Saturday, then intensify as it spreads across Northern Montana Saturday night through Sunday as strong low pressure tracks northeast over the Northern High Plains. There is high forecast confidence of 12 inches of snow Saturday night through Sunday night for eastern slopes of Montana Rockies and across North-Central Montana, including Great Falls and Glasgow. Local amounts in excess of 18 inches are likely. "

That one was written by "Ziegenfelder." That's helpful, because, now I know that the dumping of the most snow is going to happen far, far away from the Eastern Sierra in the Mt. Whitney area. If the high-level discussion mentions that the storm is going to go over California or Sierra Nevada, then I need to be more careful.

*

[freestone]

Finally, after weeks and weeks of boring weather, something interesting may happen next week. Heatwave in the PNW and monsoon over California, so if you like to be in the Sierra during a monsoon push, next week will be your chance! TS Enrique could really juice it up as well, its forecast is to ride up the coast rather than west toward Hawaii.

https://mammothweather.com/. https://weatherwest.com/archives/9778

[maverick]

Finally, after weeks and weeks of boring weather, something interesting may happen next week. Heatwave in the PNW and monsoon over California, so if you like to be in the Sierra during a monsoon push, next week will be your chance! TS Enrique could really juice it up as well, its forecast is to ride up the coast rather than west toward Hawaii.

I have been watching the weather models all month, including Enrique's path, waiting for the monsoonal flow to kick in this year. Still, as happy as I am about finally seeing it come and hopefully getting out and photograph in it next week, I am worried about the likelihood of numerous wildfires being started next week.

[aaron_in_sf]

Was planning to start the High Sierra Trail on the 29th and go north… Would someone with a better eye for reading the forecast care to comment on whether that would be a bad idea? I saw probability of up to a quarter inch of rain for example when I’d be around say precipice lake…

…No aversion to moody weather, or getting rained on; and the wind doesn’t look too bad… More wondering whether the chance of thunderstorms makes planning multiple nights at high altitude and crossing passes foolhardy; Especially when once I’m in, I am in…

[bobby49]

You generally don't spend a lot of time hovering at the pass, especially if there is a storm approaching.

A couple of years ago I was on the Whitney summit, and I could look off to the west and see a storm coming that way. So, I kind of announced to the 40-50 people on the summit that there was a storm and that they ought to get the hell off the summit. I immediately started marching downhill, and I got to the last trail junction as the first rain drops were hitting. It was cracking and booming around the summit.